The invention relates to infrared television systems, and in particular to methods and means for improving the radiant emission data processing capabilities of such systems.
The radiant emission data processing functions of an infrared television system are commonly carried out with either a filter wheel or with specially designed "rotating" filters such as the circular transmitting filter manufactured by Optical Coating Laboratory, Inc. A filter wheel, however, does not readily permit a continuous search in either time or wavelength; and circular filters do not afford the spectral resolution or large clear aperture required in most applications. Although the insertion of a series of discrete filters can also achieve similar results the transition times introduced between filter changes constitute periods during which the television system cannot view the scene without loss in optical collecting efficiency. Furthermore, all state-of-the-art devices are mechanically complex and make device cooling difficult in instances where high sensitivities are required. There currently exists, therefore, the need for new techniques and apparatus capable of providing spectral data without significant loss in system resolution, sensitivity, or optical collecting efficiency. The present invention is directed toward satisfying this need.